Methodology for the determination of the structure of the polar, poly functional aromatic compounds produced upon oxidative pyrolysis or incomplete combustion will be developed. Because of the expected complexity of the mixtures to be studied, high pressure liquid chromatography must be used for at least partial separation. For the determination of the structure of the components, high resolution tandem mass spectrometry will be employed. For this purpose the deposition device previously designed for the recording of infrared spectra of components eluting from an HPLC will be adapted to the mass spectrometer. Successful implementation of this design will permit the determination of the infrared spectra, conventional high resolution mass spectra, and the mass spectra produced upon collision induced decomposition of the same fraction of HPLC eluent.